Process for biologically transforming carbon monoxide into methane



Patented Dec. 26, 1933 omen; I sTA-r E s RooEss For: BIoLoGIoALLY TRANSFORM? r ING INTO METHANE Franz Fischer and Rudolf Lieske, Mulheim-on-i the-Ruhr, Germany No Drawing.' Application October 21,1930, Serial I No. 490,321}, and i'n'Germany November 1, 192 9 sfoiaim s. (Cl. 2e0.. =169)" j a V temperature for 20 days. The preferred tem- The transformationof. carbon monoxide and hydrogen into metl'iane'by catalytic effect (6. g.

the use of nickel catalyst) has been known fora considerable time. It has also been known: to

transform carbonic acid or. carbon dioxide biologically to methane in the presence of hydrogen by'biological. methods, butall attempts toproduce methane from carbon monoxide" by biological ,methods have proven unsuccessful,

' We now have found that it is possible, in the absence of air,"to transform. mixtures of carbon monoxide and hydrogen in the most; different proportions into methane, by the biological ac tion of certain bacterial, Inthis 'wayfit is; for

3;; example, possible to free lighting gas from the toxic. carbon monoxide without leaving"*any' trace of the latter; and withoutsubstantially reducing the calorific. effect of the gasby this proc-j ess, which cannot be achieved byiother processes for the elimination of toxic constituents.

The' effective bacteria are long, 'thinfro'ds; about 0,4,u to 0,7 in, breadth andabout 3 1. to 10,41. in length. Their edges'are rounded, they do not possess either spores or flagellums, and they are"unmotile; They are gramp ositive, but the older 'rods' aresometimes gram-negative. These bacteria, are known as plocamo-bacteria (see for instance: Lehmann Neumann; Bakteriologische' Diagnostik, 7.ed., Munich 1927, page f 5 06). They .are regularly foundf in the slime for mudflot o draining ditches, especially also in the slime or mudof Emscher tanks. The said bacteria may employcarbon monoxide as the sole carbon contai'n'ih'g sourcewithout requiring other carbonaceous nutrients.

On the usual culture-mediums, e. g. meat-extract, peptone, milk, potato,

. and the like, no accretion is to be observed. In

pure solutions, containing said bacteria, the transformation of the carbon monoxide takes ;place less perfectly than in cultures to which have been added colloidal materials, e. g. earth, putrefaction sludge, aluminium hydroxideyferric hydrate and the like.

Example 1 'flask herafter was filled with 9700 cubic cc. of illuminating gas, The flask was left at room Gas prior to-the reaction; total Gas after-the biological action;

' 9700 cm 3 i i 7 'was filled with putrefied slime or sludge taken fromEmscher tank and the tube was connected to the illuminating gas supply. The analysis of the -ga's prior and after its passage through thetube gave the following values;

Gas after passing through the Gas prior to the reaction tube 19mm Percent OO2 2.2 V .0 Hydrocarbons, espe- Hydrocarbons, especially ethylene and cially ethylene and benzol V benzol The velocity of flow ofithe-j gas passing the tube per day in this-embodiment of the process was three times the volume of the tube, the contraction and reduction innvolurne of: thegas amountedto 30%,

' For the purpose of practically applying the method for eliminating the toxic constituents from illuminating gas, the gas is made to continuously pass through systems of tubes or through fairly large containers charged with half-dry putrefaction slime or sludge from v Emscher tanks or charged with other colloidal material inoculated with the active bacteria, a gas free from carbon monoxide being obtained after passage in a corresponding manner. The velocity of flow of the gas in this process evident- 1y is dependent upon the size of the effective surface of the colloidal material.

In order to further identify the bacteria which are utilized herein, certain essential characteristics thereof are specified as follows:

Microscopic features The bacteria form small rods, occasionally also long filaments, in an inorganic nutrient, in a chamber filled with a mixture of carbon monoxide and hydrogen.

Spores.Absent.

FZageZZa.-Absent; motility not observed.

OoZourabiZity.Colourable with methylene blue, phenylate of fuchsine and crystal-violet.

The small rods in young cultures are grampositive, gram fastness smallj older rods are gram-negative.

Biochemical reactions Not pathogenic for white mice.

The bacteria are capable of employing carbonmonoxide as the sole source of carbon.

Relation to oxygen.--Strictly anaerobic.

Gelatine Ziquefaetiona-Negative.

In nitrate media.No gas, no nitrate.

'Chromogenesis.Absent.

Carbohydrate reactions Diastatic action.Negative.

From cane sugar From milk sugar From glucose sugar Neither acid nor gas.

Vegetative cells Diameter.--Between 0",5,a and 1a. Length.More than double the diameter. Chains.Absent.

CapsuZes.-Absent.

Spores Not observed.

Cultural features Physiology Optimum temperature: 30 C.

Maximum temperature: 60 C.

' Minimum temperature: l0" C.

Chro1nogenesis.Absent.

Production of indoZ.Absent. I Production of hydrogen sulphide-Absent;

Relation to oxygen Nitrate reduction-Not observed; no gas.

Fermentation Dextrose Lactose Saccharose Glycerin Not fermented.

Special tests The bacteria are multiplied rapidly in an atm'osphere containing carbon monoxide and hydrogen; they are strictly anaerobic and are capable of employing carbon monoxide as the sole source of carbon.

The bacteria grow well in a nutrient consisting of distilled water 100 parts, (NH-1)HPO4 0.05 parts, and K2HPO4 0.01 parts, with a superposed gas mixture of A; CO and H2. The nutrient grows slightly turbid, no formation of surface layer or skin isobserved.

Having now particularly described and ascertained' the nature of our said invention, we declare that what we claim is:

' 1. A process for biologically transforming carbon monoxide into methane, consisting in exposing carbon monoxide in the presence of hydrogen to the action of gram-positive, non-sporuliferous plocam'o-bacteria of the typed'esc'rib'ed.

2. A process for biologically transforming car: bon monoxide into methane, consisting in exposing gas mixtures containing carbon monoxide in the presence of hydrogen to the action of gram-positive, non-sporuliferous plocamo-b'a'm teria of the type described. I

3. A process for biologically transforming carbon monoxide into methane, consisting in expos- 115 ing carbonmonoxide in thepresence of hydrogen and of colloidal materials to the action of grampositive, non-sporuliferous plocamo-bacteria 01' the type described;

' 4. A process for biologically transforming car'- bon monoxide into methane, consisting in exposing gas mixtures containing carbon monoxide in" the presence of hydrogen'and'of colloidal mate-v rials to' the action of gram-positive, non-sporuli'ferous plocamo-bacteria of the type described. 128

5. A process for biologicallytransforming carbon monoxide into methane, consisting in exposing'oarbon monoxide in the presence of hydrogen to the action of bacteria of the type found in the sludge of an Emscher tank.

FRANZ FISCHER. RUDOLF LIESKE. 

